High Energy Physics Seminars this week (Riembau Saperas and Notari)

[HECAP - Margherita Di Giovannantonio]

*_HIGH ENERGY PHYSICS SEMINARS_**__*



*Tuesday, 20 February* 2024, at *16:00*  - *LUIGI STASI SEMINAR ROOM/
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Marc Riembau Saperas (CERN)

*“Positivity for Real World Phenomena”*

_Abstract_

In recent years it has become apparent that unitarity and causality of 
QFT dramatically constrain the allowed space of consistent IR dynamics. 
In this talk I present how the electroweak parameters are constrained 
due to the particular structure of universal theories,  a broad class of 
well-motivated microscopic dynamics of the electroweak sector that go 
beyond the Standard Model description. In particular, the W and Y 
parameters are constrained to be positive by unitarity and are 
necessarily the leading effects at low energies. I discuss how this 
observation affects the interpretation of current data and assess the 
impact of future constraints.



<https://indico.ictp.it/event/10616/>

This is a hybrid event. *To join via Zoom*:

Zoom link:https://zoom.us/j/94267507215

Meeting ID: 942 6750 7215

Password: 178365



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*Thursday, 22 February* 2024, at *16:00*  - *LUIGI STASI SEMINAR ROOM/
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Alessio Notari (Galileo Galilei Institute for Theoretical Physics)

*“Gravitational Waves and Primordial Black Holes from Domain Walls: 
Implications for PTA and Dark Matter ”*

_Abstract_

Unstable domain wall (DW) networks in the early universe can emit a 
large amount of gravitational waves (GW) before annihilating. In the 
context of the recent GW signal reported by Pulsar Timing Arrays (PTA) 
collaborations, I will explore them as a possible interpretation. Next, 
I will address a crucial question: do unstable Domain Wall networks also 
lead to significant production of Primordial Black Holes (PBH)? I will 
then present two main consequences. Firstly, I will assess the 
compatibility of the DW interpretation of the PTA signal with 
observational constraints on PBHs. Secondly, I will consider the 
possibility that Dark Matter can be entirely in the form of 
asteroid-mass PBHs, resulting from the DW collapse. In this case, I will 
demonstrate that observable GW signals should be detectable at 
interferometers (such as LIGO-Virgo-KAGRA and future instruments like 
LISA and Einstein Telescope).



<https://indico.ictp.it/event/10616/>

This is a hybrid event. *To join via Zoom*:

Zoom link:https://zoom.us/j/92253271346

Meeting ID: 922 5327 1346

Password: 170232